Silicone Hydrogel
Contact Lenses
The Capabilities of Silicone Hydrogel Contact Lenses
The latest improvements which hit the contact lens market
are silicone hydrogel contact lenses. Being known as a soft
contact lens, this new material has taken over the rigid gas
permeable contact lenses in the areas of comfort and clarity.
It all comes down to the material that's used. Different
from the standard soft contact lenses that have been made
using a considerable amount of water, these contact lenses
contain silicone. Silicone is highly gas-permeable and as
such it allows the free flow of ample amounts of oxygen through
each of the lenses. Such a flow will ensure that the cornea
gets a continuous supply of oxygen which then promotes a healthier
eye.
When the cornea has enough oxygen, the corneal epithelium
will be more prone to remain intact and that's necessary for
ensuring clear and acute vision. When the epithelium breaks
down, microbial keratitis may become an issue. The new lenses
with low water content, are also effective at keeping bacteria
from adhering to the lens surface. That greatly reduces the
likelihood of a microbial infection.
Another advantage of these lenses is due to their low water
content, they are less likely to dry out after extended periods
of wear. And this is so different from the standard soft contact
lenses which often dehydrate and need constant replacement.
More over, the plastic materials used in soft lenses are not
gas permeable which means that oxygen can only reach the cornea
by passing through the water. Since water is far less permeable
than silicone, insufficient oxygen might become a risk.
If you prefer extended or continuous wear contact lenses,
then this is the good choice for you. Several contact lens
manufacturers have invented silicone hydrogel contact lenses
which can be worn up to 30 days, day and night, without needing
to be removed. At the end of the 30-day period, the pair will
be thrown away and a new pair is inserted. Most brands using
silicone, however, are still only approved for 7-day usage.
If a person is comfortable with extended wear lenses, and
has obtained the correct prescription, silicone hydrogel contact
lenses will be a very affordable and choice to afer alternative
to undergoing LASIK eye surgery.
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